Hydraulic wedge



C. B. EVENSON HYDRAULIC WEDGE Nov. 3, 1953 2 Sheets-Sheet 1 Filed Aug. 25, 1949 m x 15m OR. c'hrjlszo vizerfi. Even son ATTORNEYS Nov. 3, 1953 c. B. EVENSON 2,657,904

HYDRAULIC wanes Filed Aug. 25, 1949 2 Sheets-Sheet 2 INVENTOR. 7 6'22 nwzoph erfi. Even son ATTORNEYS Patented Nov. 3, 1953 UNITED STATES PATENT OFFICE 2 Claims. 1

This invention relates to a hydraulic wedge, and" more particularly to a hydraulic wedge adapted who used in felling heavy trees.

The object of the invention is to provide a hydraulic wedge which is adapted to be actuated by a power chain saw and wherein the wedge serves to prevent the saw from being pinched during the cutting of timber.

Another object of the invention is to provide a hydraulically operated wedge wherein a manually operable means is provided for regulating the movement of thewedge, the wedge being strong and eflicient in its operation.

A further object of 'the invention is to provide a hydraulic wedge which is extremely simple and inexpensive to manufacture;

Other'objects and advantages will be apparent durin the course of the following description.

In the accompanying drawings, forming a part of this application, and in which like numerals are used to designate like parts throughout the same:

Figure 1 is a top plan view of the wedge, according to the present invention;

Figure 2 is'a side elevational' view of the wedge, with parts broken away and in. section;

Figure 3 is a sectional view taken on the line 33 of Figure 1;

Figure 4 is a side elevational view of. thepump, with parts broken away and in section;

Figure 5 is a longitudinal sectional view taken. through the valve for controlling the flow of fluid to the wedge;

Figure 6'is an end elevational view of the valve shown in Figure 5;

Figure '7 is a side elevati'onal. view showing the assembled wedge unit ready for use.

Referring in detail to the drawings, there is shown a hydraulically operated wedge assembly which includes a wedge unit III. The wedge unit I includes a cylinder l I' that has a pair of body members I2 and I3 connected thereto. Each of the body members 12 and I3 is provided with a plurality of teeth M on its front end whereby the body members l2 and I3 will not accidentally slip out of a cut. in a tree or the like when the device is being used.

For pivotally connecting thebody members l2 and I3 to the cylinder H, a pair of barsv l are.

arranged on the side of the cylinder H. One end of the bar I5 is connected to the cylinder II by' bolts or pins it, while the other end of the bars I'5 is pivotallyconnected' to the body members l2 and I3 by suitable headed pins I1.

Mounted for reciprocatory movement in the cylinder l I is-a piston It and secured to the front end of the piston I8 is a triangular shaped wedge l9 which is mounted for sliding movement between the body members l2 and I3. actuation of the piston l8, the wedge 19 will move tothereby selectively spread the body members l2 and [3. A flexible conduit 20 serves to convey hydraulic fluid from a source of supply intoa passageway 2| which leads to the interior of the cylinder l I, Figure 2', and this hydraulic fluid serves to actuate the piston I8. Further, a means is provided for insuring that proper lubrication is provided between the Wedge l9 and the body members 42' and I3. Thus, a plurality of ball bearings 22 are positioned in sockets 23 in the body members 12' and I3, a portion of the ball bearings 22 projecting into passageway M in the wedge I9. A passageway 25- serves to convey hydraulic fluid from the interior of the cylinder H to a conduit 26- which in turn communicates with the passageway 24 in the-wedge I 9- and the conduit 26 also communicates with passageways 21 in the body members l2 and I3. It is to be noted that there are a plurality of the passageways 25 and 21 so that lubricating fluid is conveyed to all necessary moving parts of the wedge unit. A valve 28 is interposed between the passageway 25 and the conduit 26 for controlling the flow of lubricating fluid therethrough.

The cylinder H is provided with an overflow port 29 whereby in the event that a piston 18 moves too farforwardly'in cylinder H, a portion of the hydraulic fluid will pass out through the overflow port 29 to warn the operator and prevent movement of the piston [8 completely out of the cylinder I I.

A means is provided for normally urging body members l2 and I3 toward each other. This means: is shown in detail in Figure 3, and includes a clamp 39 which is provided with a support member 3! that is arranged in engagement with the body'member 13. The support member 31 is provided: with a pair of spring legs 32 and 36. The leg 32' terminates in a threaded portion 33 which projects through an opening in the body member l2, and a bracket 34 is arranged in engagement with the. portion 33 of the leg 32. A nut 35- is arranged in engagement with the portion 33 for maintaining the parts in assembled relation. Similarly, the other coil spring leg 36 terminates in a threaded portion 3T which projects through an opening in the body member 12, and the other end of the bracket 34 is arrangedv in engagement with the portion 3T of the leg 36. A nut 38 serves to maintain these parts in assembled relation. Thus, it will be. seen that the constructionof the clamp 30 permits the Thus, upon '3 (J body members l2 and |3 to separate or spread apart as the wedge I9 is moved therebetween, since the clamp 39 includes spring legs 32 and 36. Normally, the clamp 30 urges the body members l2 and I3 toward each other.

Referring to Figure 7, there is shown the assembled hydraulic wedge unit which is ready for use. This assembled unit includes a tank 39 which is adapted to contain hydraulic fluid therein. A pump 49 is adapted to transfer hydraulic fluid from the tank 39 to the cylinder II, and the pump 40 is actuated by a saw 4| as described later in this application. For controlling the flow of hydraulic fluid through the conduits, a valve assembly 42 is provided and this valve assembly is described in detail later in this application.

The rnanually operable valve 42, Figure 5, includes a housing 43 that has a base 44 immovably mounted therein. Also arranged in the housing 43 is a movable block 45. A bolt and nut assembly 46 pivotally connects the block 45 to the base 44, and a pair of bore: .1 and 48 are arranged in the base 44. The conduit 29 communicates with the bore 4! while a flexible conduit connects the bore 48 to the tank 39.

The movable block 45 is provided with a pair of bores 49 and at which are adapted to be moved into and out of registry with the bores 4! and 48 in the base 44 so that the flow of hydraulic fluid to the wedge units can be controlled as desired. A hand lever 52 projects through a slot 53 in the housing 43 and into engagement with the block 45 for rotating or moving the latter. A conduit 54, which is flexible, connects the bore 49 to the pump 40, and a flexible conduit 55 connects the bore 50 to the pump fli later described in this application. A conduit connects the tank 39 to the pump 40, there being a manually operable valve 51 interposed in the line 56 for controlling the flow of fluid therethrough.

For transfer-rim hydraulic fluid to and from the wedge unit H), a pump 40 is provided, and the pump 49 includes a casing 58 which has a chamber 52 arranged centrally therein. A plunger 59 is slidably mounted in the chamber 62, and the plunger 59 is maintained in alignment or guided by a bearing 3| which is supported by a bracket, the bracket 65) being secured to the casing 58, Figure 4. A coil spring 63 is circumposed on the plunger 59 for normally urging the plunger 59 into its outermost position. A check valve 64 is arranged in the casing 58 for preventing hydraulic fluid from passing from said pump 40 back through the line or conduit 55. valve 65 is also arranged in the end of the casing 58 for preventing hydraulic fluid from accidentally passing from the conduit 54 back into the pump 40.

The pump 4% is adapted to be actuated by a power driven chain saw 4|. The saw assembly 4| includes a rotatable driven shaft 66 that has mounted thereon a cam 6i, and the cam 61 arranged in engagement with a roller 58 that is mounted on the end of the plunger 59. Thus, upon actuation of the chain 4|, the cam 6! will rotate to thereby reciprocate the plunger 59 in the chamber 62 so that hydraulic fluid can be forced to and from the wedge unit [0.

Projecting from the cylinder H of the wedge unit In and secured thereto, or formed integral with the pair of eye bolts 69 and I0 which are used when the wedge unit is to be supported from a supporting structure.

The operation of the device is as follows:

A check iii Enl

When it is desired to fell a large tree, a face cut is made in the tree by means of a suitable saw. It is well known that during the sawing of trees, the parts of the tree tend to bind on the saw whereupon further movement of the saw is pre vented. Thus, by means of the present invention, the upper and lower parts of the tree can be maintained separated or spread apart sufficiently so that binding of the saw blade will be prevented. Thus, after the face cut in the tree has been made, the wedge unit I0 is positioned therein, and with the valve 42 in the position shown in Figure 7, hydraulic fluid will be forced into the cylinder II by the pump 40. The pump 40 is adapted to be actuated by the cam 61 on the saw assembly 4| and thus, hydraulic fluid will be drawn from the tank 39 through the conduit 5|, then through the valve 43, and through the conduit 55. This hydraulic fluid then passes through the pump 40, out through the conduit 54, and then into the cylinder by means of the conduit 20. As the hydraulic fluid enters the cylinder II, the piston l8 will be moved or forced outwardly to thereby start to eject the wedge |9 whereupon the body members I2 and I3 will be spread to separate the portion of the tree being felled. By reversing the block 45 by means of the hand lever 52, the flow of fluid can be reversed in the conduit so that the piston I8 and wedge H can be retracted inwardly into the cylinder whereupon the resiliency of the clamp 39 will cause the body member l2 and the body member l3 to move toward each other in the position shown in Figure 2.

The wedge unit of the present invention is durable, and efficient in operation. The wedge unit it constructed so that ample lubrication is provided between the moving parts by means of the ball bearing 22 and the conduits 25 which serve to convey lubricating or hydraulic fluid to the space between the wedge and body members l2 and I3.

What I claim:

1. In a hydraulically operated wedge unit, a cylinder, a pair of body members mounted for movement toward and away from each other, a plurality of spaced parallel bars pivotally connecting said body members to said cylinder at one end thereof, each of said body members being provided with a plurality of teeth on its front end, a piston reciprocably arranged in said cylinder, a triangularly-shaped wedge secured to the front of said piston and slidably positioned between said body members and adapted to extend outwardly of said cylinder intermediate of the pivotal connections of said body members to said parallel bars, a flexible conduit for conveying hydraulic fluid from a source of supply to the interior of said cylinder, means for conveying hydraulic fluid from the interior of said cylinder to and between said wedge and body members for insuring proper lubrication therebetween, valve means for controlling the last-named flow of hydraulic fluid, there being an overflow port in said cylinder, and resilient means for normally urging said body members toward each other.

2. In a hydraulically operated wedge unit, a cylinder, a pair of body members mounted for movement towards and away from each other, a plurality of bars pivotally connecting said body members to said cylinder, each of said body members being provided with a plurality of teeth on its front end, a piston reciprocably arranged in said cylinder, a wedge secured to the front of said piston and slidably positioned between said and between said wedge and body members for 5 insuring proper lubrication therebetween, valve means for controlling the last named flow of hydraulic fluid, there being an overflow port in said cylinder, and resilient means for normally urging said body members towards each other.

CHRISTOPHER BRADY EVENSON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date Marshall Dec. 30, 1890 Breeden Oct. 13, 1925 Hensen Oct. 31, 1933 Long Feb. 8, 1944 Young Sept. 25, 1945 Miller Feb. 14, 1950 Anuszkiewicz May 2, 1950 

